In September 2005 issue of Scientific American Journal, there was an article: “The Big Potential of Small Farms” by Paul Polak (August 22, 2005). Paul Polak started IDE—International Development Enterprises—in 1981 to come up with good solutions to water problems. The article describes IDE’s work and the problems they are trying to solve.
There’s a graph of Water Scarcity.
Here’s a quote: “Water scarcity takes its highest toll on small farmers, many of whom must eke out a living in semiarid areas far from well or reservoirs. About half the world’s hungry people are farmers who work small plots of land; another 20 percent are landless farm laborers who live in rural regions.”
“Individual irrigation systems employing inexpensive equipment, such as drip lines and storage tanks, can greatly enhance the yields of small plots. If farmers raise high-value crops such as tomatoes or chili peppers, they can boost their earnings by as much as $500 a year.”